Effects of environments and cultivars on grain ionome of spring wheat grown in Kazakhstan and Russia

Abstract

Kazakhstan–Siberian Network on Spring Wheat Improvement unites 18 spring wheat (Triticum aestivum L.) research and breeding programs and presents opportunities to study genotype × environment interactions. Trial data from six locations in Kazakhstan and Russia in 2017–18 were used for grain ionomics analysis to evaluate the relative contributions of environment and genotype to variation in elemental composition and to formulate a methodology to enhance concentrations of important minerals in grain. The effect of year was least important to variation. For several elements (P, S, Cu, Mn and Mo), the effect of site was 2–3 times higher than the effect of genotype. The effects of genotype and site were similar for Ca, Mg, Fe, Cd and Sr concentration. Average broad-sense heritability across six sites in both years was: (for macroelements) Mg 0.59 > Ca 0.50 > K 0.44 > P 0.30 > S 0.20; and (for microelements) Zn 0.44 > Mn 0.41 > Cu 0.40 > Fe 0.38. Biplot analysis grouped the traits into five clusters: (1) concentrations of Co, Cu, Mo and Sr; (2) concentrations of Mg, P and Zn; (3) concentrations of K and Ni; (4) protein content, concentrations of Cd, Fe, Mn and S; and (5) grain yield, concentrations of Ca and Rb. These associations reflect regional soil and environment variation independent of genotype. Protein content had positive and significant genotypic correlations with Mg (0.57), P (0.60), S (0.68), Fe (0.64), Cu (0.50), Mn (0.50) and Zn (0.53). A combination of high grain yield, relatively high protein content, and high concentrations of P, S, Mn, Cu and Zn (singly or combined) was identified in the genotypes Element-22 (check cultivar), Lutescens-3-04-21-11, and Silach. The study contributes to research and cultivar development to improve the nutritional profile of grain for consumers.

Genetic Characterization of Spring Wheat Germplasm for Macro-, Microelements and Trace Metals

“…The series of ionomics studies with spring wheat in the region allows the development of a breeding strategy and methodology to enhance the elemental composition. Two previous ionomics studies in Northern Kazakhstan and Western Siberia [14,15] demonstrated a large effect of protein content on the concentration of both macro-and microelements. Concentrations of Fe, Mn, and S were positively correlated with protein content on both environment and genotype levels.…”

“…The analysis of genotype by environment interactions for the KASIB trials showed that genetic improvement for all elements would be highly affected by the uniformity of experimental fields [14]. Broad sense heritability values demonstrated substantial variation between sites and years for all elements.…”

“…The contribution of three genomes to MEAs also varied among elements. A genome-hosted highest number of MEAs for K; genome B for Mg, P, Mn, Zn, Co, Ni, and Sr; genome D for Ca and S. Group 1 SNPs with significant MEAs in the two years were identified for Ca (3), Mg (14), P (5), Cu (1), Mn (8), Cd (13), Co (1), Ni (3) and Sr (2) (Table 1 and Supplementary Table S3). There were 197 Group 2 SNPs with −log 10 (p-value) > 3.5 and significant effects for original and adjusted values in one year for all elements with exception of Rb.…”

“…The ranking of the remaining elements using the number of reliable MEAs was P (11 MEAs listed in Tables 2 and 4), Mg (9), Cd (9), Ca (7), Mn (7), Zn (3), Sr (3), S, Cu, Ni and Mo (1 each for the latter 4 elements). Previous ionomics study of KASIB multilocational trial [14] rated the elements according to broad-sense heritability values: for macroelements, Mg (0.59) > Ca (0.50) > K (0.44) > P (0.30) > S (0.20); for microelements, Zn (0.44) > Mn (0.41) > Cu (0.40) > Fe (0.38); and for trace elements, Mo (0.56) > Sr (0.55) > Co (0.49) > Cd (0.44) > Ni (0.37) > Rb (0.31). Obviously, there is some confirmation of the elements' suitability for genetic enhancement based on higher H 2 values and the number of MEAs with significant effects identified in the present study; elements Mg, Ca, Cd and Mn.…”

“…A genotype × environment study was based on a multilocational trial of the Kazakhstan-Siberia Network on Spring Wheat Improvement (KASIB) with 49 entries at six sites in two seasons [14]. The effect of year was least important to variation in grain ionomics composition.…”